High-viscosity liquid

Economic Pipe Diameter, Laminar Flow Pipehnes for the transport of high-viscosity liquids are seldom designed purely on the basis of economics. More often, the size is dictated oy operability considerations such as available pressure drop, shear rate, or residence time distribution. Peters and Timmerhaus (ibid.. Chap. 10) provide an economic pipe diameter chart for laminar flow. For non-Newtouiau fluids, see SkeUand Non-Newtonian Flow and Heat Transfer, Chap. 7, Wiley, New York, 1967). 

For the flow of high-viscosity liquids over rectangular weirs, see Slocum, Can. ]. Chem. Eng., 42, 196-200 (1964). His correlation is based on data for liquids with viscosities in the range of 2.5 to 500 Pa s (25 to 5000 cP), in which range the discharge decreases markedly for a given head as viscosity is increased. 

Pressure. Flow 0t(AP/pd - Only source of energy is from fluid being atomized. Simplicity and low cost. Limited tolerance for solids uncertain spray with high-viscosity liquids susceptible to erosion. Need for special designs (e.g., hypass) to achieve turndown. 

These mixers are specified when one liquid must be dissolved in another, a solid and a liquid must be mixed, a high viscosity liquid must be reacted, a light liquid must be extracted from a mixture of heavy and light liquids, or when gas must be absorbed in a liquid. To select the proper mixer, certain fluid properties must be know n ... 

Observable Characteristics - Physical State (as shipped) High-viscosity liquid Color Colorless Odor. Odorless. 

It is better able to handle high viscosity liquids and slurries. 

Anchors, helical ribbons and screws, are generally used for high viscosity liquids. The anchor and ribbon are arranged with a close clearance at the vessel wall, whereas the helical screw has a smaller diameter and is often used inside a draft tube to promote fluid motion throughout the vessel. Helical ribbons or interrupted ribbons are often used in horizontally mounted cylindrical vessels. 

Kneaders, Z- and sigma-blade, and Banbury mixers as shown in Figure 7.20, are generally used for the mixing of high-viscosity liquids, pastes, rubbers, doughs, and so on. The tanks are usually mounted horizontally and two impellers are often used. The impellers... 

Thermosyphon reboilers are usually cheapest but not suitable for high-viscosity liquids or vacuum operation. Further discussion of reboilers will be deferred until Chapter 15. In the preliminary phases of a design, it is best to assume that enough stages are available in the column itself to achieve the required separation. 

Mixing a high-viscosity liquid with one of low viscosity reduces the viscosity just because of the dilution of the polymer. 

Can handle two-phase, foamy, and high-viscosity liquids. 

In general, centrifugal pumps are less expensive, last longer and are more robust than positive displacement pumps. However, they are unsuitable for pumping high viscosity liquids and when changes in viscosity occur. 

The second group is more effective than the first in the mixing of high viscosity liquids. 

Recently, Knoll and Sojka[263] developed a semi-empirical correlation for the calculation of the Sauter mean diameter of the droplets after primary breakup of flat-sheets in twin-fluid atomization of high-viscosity liquids ... 

Derived from spray data for high-viscosity liquids (mixtures of glycerine and water) of 50flows through discharge slots and impacts both sides of a flat liquid sheet from a discharge slot inbetween the air slots) Droplet size measured by Malvern 2600HSD Spray Analyzer Effects of air slot thickness included... 

Spinning discs are very suitable for slurries and pastes, while high viscosity liquids tend to produce a stringy product. Care must also be taken in design to minimise incrustation around the lip and subsequent out-of-balance as drying takes place. 

Amorphous. Strictly speaking, characterized by noncrystalline structure, i.e., having no. lattice structure that most solids have. Liquids are amorphous. Glass is a solid but is amorphous because it is considered a high viscosity liquid.. 

Apart from the critical impeller speed for solid suspension and efficient gas dispersion, flooding is also a very important phenomenon in three-phase systems. Flooding may take place at low impeller speed or high gassing rate. Under these conditions, the gas is dispersed just around the central shaft of the tank, whereas the solids are settled at the bottom. Flooding characteristics are not affected by particles. Furthermore, high-viscosity liquids are able to handle more gas before flooding than low-viscosity liquids. 

Viscosity The thickness of liquids the degree to which or the ease with which a liquid flows usually increases when temperature decreases. A liquid with a low viscosity will flow very rapidly and any spill of that liquid will create problems very quickly a high viscosity liquid will not flow as easily and can therefore be controlled more readily should it spill. 

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